This invention relates to a curb mold and extruding system used in forming concrete, cement or other building materials into curbs, gutters, barrier walls, sidewalks, and the like quick and easily on construction projects.
The present invention relates to a mold used for concrete formation. More particularly, it relates to an extrusion molding device, which when connected to a conventional concrete pump, or other like apparatus, extrudes concrete, cement or other similar building materials into a multitude of shapes to be used in the construction field as curbs, gutters, barrier walls, sidewalks, and the like. In the past, it has been necessary to use hand placed, wood, or metal forms to be assembled, taken apart, and reassembled through out the project. This process is labor and time intensive, requiring the material to harden before the molds may be removed. In the area of sidewalks, the concrete must be roughly smoothed between the forms, this is called screeding, then it is float finished with either a bull float or hand float. The edges must be finished with an edging tool, then, after the material has reached a desired degree of hardness, it is hand or machine finished with trowels to a smooth surface and given any number of textured surfaces, the most common being a broom finish.
In the act of constructing extended concrete structures, a control or expansion joint must be installed periodically by either scribing or inserting a fiber or metal insert. When concrete is placed between forms, varying degrees of water may be added to allow ease of spreading. This is usually left to the digression of the finishers, sometimes to excess, which they call self-leveling. Too much water in concrete decreases the hardness or pounds per square inch (PSI) hardness rating of the material, it also allows a separation of materials with the rock and reinforcing bar going to the bottom.
When concrete is dispensed through a pump, the water content may be strictly controlled producing a harder and more consistent grade of material, with written verification available, if required. A broad range in size and capabilities of portable concrete pumping services are available in most cities, where the pump is towed behind or part of a separate vehicle, and material is dispensed from a supply truck into the pump hopper and pumped through a hose to the desired location. Reinforcement of the extruded material may be accomplished through the introduction of various fibrous materials, such as polypropylene fiber, called fiber mesh. This material strengthens the structure mainly against the small hairline cracks and spalling caused by freezing, but does not help with the large cracks caused by heaving of the ground in the areas with alluvial soils, or lack of adequate compaction of the underlying soils. Nothing can replace the structural strength of a continuous reinforcing bar added to the building material.
Many types of curb forming machines have been developed, from large slip-form machines used in freeway construction, to the smaller curb forming and extruding machines used in general construction. In most of these machines, the construction material must be manually placed into the hopper, on the device where it is either manually or mechanically transported by pressure into the extrusion cavity. Such devices require an engine or pump onboard the formation machine itself and render it heavy, requiring a power source, and otherwise inconvenient. The weight and the adhesion of the material to the surface along with the pressure pushing the material into the extrusion cavity propels the device in a forward direction, although being difficult to go up or down inclined surfaces, because of the excessive weight of the apparatus. In general, these machines use an attached motor to supply the driving force required, making them very cumbersome even in the lightest models. The act of adding reinforcing bar is made difficult, due to the required location of the auger or plunger pushing the material into the extrusion cavity. Some manufactures claim reinforcing bar is not necessary with the introduction of fiber mesh, which is not correct.
Cleaning concrete equipment and keeping it clean is a major problem in the industry. When concrete is left on any tools or equipment for a period of time it is extremely hard to remove, thus a piece of equipment with many moving internal parts is very hard to keep clean.
Transportation of the material to the extruding equipment from the mixer or truck is another major problem with the conventional curb machines where the hopper must be loaded by hand and the material transported by wheelbarrow. These processes being difficult with small extrusions where minimal amounts of material are required are impossible with larger cross sectional areas, as in side walks and road dividers.
U.S. Pat. No. 4,566,823 by George N. May describes a manually operable curb extrusion device for extruding curb, barrier, or the like from concrete, cement, or some other moldable building material. The building material is manually placed in a receiving hopper and falls into a compacting chamber where a power driven reciprocating compacting member compacts the material into the extrusion mold where it is shaped before extrusion. There is no means to insert reinforcing bar into the cavity because the inventor states that with the use of fiber mesh it is not required; although, on some Municipal and Federal contracts reinforcing bar is required. This device would not be capable of any large cross sectional concrete extrusions.
U.S. Pat. No. 5,527,129 by Paul G. McKinnon discloses a manually operable and steerable curb extrusion device for extruding curb, barrier, wall, gutter, or the like from concrete, cement, or some other moldable building material. The curb extrusion device has a hopper into which building materials are placed to fall into a reciprocating orbital compaction member which compacts, kneads, and forces the building materials through an open-ended extrusion mold where it is shaped before extrusion. This is another motorized concrete compressing device supplied with a hand fed hopper. Here again not capable of large cross sectional concrete extrusions and labor intensive.
U.S. Pat. No. 5,354,189 by Paul M. McKinnon additionally discloses a manually operable and steerable curb extrusion device for extruding curb, barrier, wall, gutter, or the like from concrete, cement, or some other moldable building material. The curb extrusion device has a segmented vibrating hopper into which building materials are placed to fall onto two tapered vibrating augers that compact and force the building material through an extrusion mold where it is shaped before molding. This is another motorized curb extruding device. Though larger with a vibratory action and two steering wheels, it requires a wider operating footprint to be cleared prior to the operation and also relies on the hopper being manually filled.
U.S. Pat. No. 5,018,955 by Robert W. Parrish teaches of an apparatus for shaping and extruding concrete or other moldable material as a decorative curbing. Moldable material is placed in a hopper and flows into an auger which compresses, mixes, and extrudes the material through a shaped, non-flanged mold into the desired curb bed. A fueled engine or electric motor drives a hydraulic pump to pressurize hydraulic fluid. The pressurized fluid drives a hydraulic motor which turns the auger. This device, having greater capacity and a more controlled power source, would require an even wider footprint to be cleared prior to operation and still requires the hopper to be hand fed. U.S. Pat. No. 4,310,293 by Richard C. Eggleton describes a machine for compacting and molding concrete mix or other plastic materials. This machine incorporates a powered ram plate which reciprocally moves from a first position adjacent to the body structure to a second position wholly within the molding member, picking up the material from the base of the hopper. This machine is supported on three or four or sometimes more than four wheels. This is another motorized, hopper-fed, wide curb machine.
U.S. Pat. No. 3,733,141 William T. James teaches of a machine for forming curbing consisting of a manually operable, steerable device which compacts and shapes asphaltic concrete or portland cement mixes having no slump characteristics into uniform curbing. Though manually operated, this device utilizes the same principal of a plunger pushing material through the base of a manually filled hopper into a molding chamber, driving the device forward. This device would definitely not be capable of extruding any appreciable size or length of curbing and demands a great deal of exertion by the operator as well as the individual filling the hopper.
U.S. Pat. No. 3,585,911 by John Vlasic describes a curbing apparatus consisting of a manually operable wheeled vehicle for forming curb mix asphalt into a uniform curb. The vehicle carries a curb forming shoe with a hopper thereabove and a manually controlled shutter and plunger. This manual apparatus is not capable of extruding appreciable size or lengths of curbing.
U.S. Pat. No. 3,566,760 by Napoleon G. Lafleur et al. discloses a paving machine for laying asphalt, preferably in a double-curbed channel form. This device in no way will operate in the manner to extrude any quantity of concrete curbing.
All of these hopper-fed machines could be supplied by a conventional concrete pump, but would in no way be able to handle the capacity of building material available through this means.
There is a pressing need for a simple curb mold and extruding system which does not require a motor or storage hopper to be manually filled, which does not require a wide area to be cleared to operate in and can lay down an unlimited amount of curbing with reinforcing bar, in a great number of cross sectional shapes, from freeway barriers to small curb forms, that can lay down a curb as straight as a laser beam as well as curves of varying diameters, and that can go up as well as down inclined slopes with ease. There is a need for a new and unique system that requires fewer laborers with much less exertion required and is easily cleaned upon completion of the project.
These and many other ramifications in the field of concrete and other like building materials used on construction projects will be greatly simplified with the incorporation of this new and unique invention.
The present invention accomplishes its desired objects by providing a system of injecting the concrete, cement, or any other similar building material, by a remote pump, into a unique mold which extrudes the desired curb, gutter, barrier wall or sidewalk while moving under control of an operator. A remote trailer mount or vehicle mounted pump is conventionally located adjacent to the building material supply truck. The driver of the material supply truck keeps the hopper of the pump full, while the pump is controlled by an operator with a wireless remote standing near the end of the distribution hose, with additional lengths of hose to be added during the process. The hoses on these contract pump units, being in segments, commonly exceed one hundred feet in length. Material supply trucks are changed without interrupting the flow, due to the large capacity of the pump""s hopper. The hose and pump can have a wide range of sizes and capabilities depending upon the required output, and can deliver an unlimited amount of material as long as desired. This factor can make possible a wide range in sizes of molds, controlled only by the capabilities of the pump available.
The operator will stand in front of the mold that is attached to the end of the pump hose, holding the handle to guide it in the desired direction with one of a number of different guidance means, and very little effort required. A laborer would conventionally stand in close proximity to the mold holding the hose, generally over his shoulder, allowing the mold to fill and traverse forward propelled by the pressure of the material in the mold cavity. Generally, several laborers are required to watch and maintain the hose to insure a smooth and continuous flow of material and that the hose does not kink.
Weights are added to the top of the mold to keep it from lifting too much due to the pressure of the pump, although through the process the mold will float approximately one inch above the surface. The height of the leading end of the mold may be adjusted by a number of different elevator wheel means determined by the character of the mold. The length of the back of the mold or extrusion cavity determines the shape and smoothness of the extrusion, a longer length giving a smoother finish, though not capable of making as sharp a radius. Sections may be added to the mold to increase the length as desired.
Alignment brackets mounted to the side of the mold retain a string line that the operator will follow to maintain a straight line. An optional and advanced method for alignment and elevation correction would be a laser line to a computer controlled, motorized gearbox mounted on the elevator post of the guide wheel. This box could make adjustments in elevation through a system of gears and also indicate alignment corrections required by a beeping sound. Another adaptation of the laser system would have the laser activated box beep, or lights blink, both for up and down and side to side adjustments required, with the operator making them manually.
Reinforcing bar is fed through one or more reinforcing bar insertion tubes in the leading end of the mold by a laborer. These insertion tubes also provide a means to vent trapped air from the inside of the mold cavity, but are too small to allow any appreciable amount of material to go through. An optional tubular member on top of the mold allows for the insertion of the stinger or head end of a hand-held vibrator, commonly used in the concrete industry, to be attached, thus increasing the compaction of the material. Using this system, the material can have less water incorporated into the mix, producing a higher PSI, or pounds per square inch hardness rating. In some configurations, the mold will be segmented, the lead end being the compression chamber, the back being the extrusion cavity. The extrusion cavity may consist of several segments extending any given length with some incorporating surface treatment devices such as a control joint cutter or an edge tool. This also allows that one compression chamber will fit a variety of different styles of extrusion chambers.
Preparation for the process is greatly simplified by the fact that only a narrow strip needs to be set to grade before initiating the process, sometimes as little as 12 inches, depending upon the width of the mold. If a straight section is desired, a string or laser can be set up, adjacent to the graded strip, to maintain straightness. Otherwise, a predetermined chalk or paint line on the surface would be all that is required for the operator to follow. Levels mounted on top of the mold can give parallel and transverse level indications on level surfaces only. A small form must be placed at the beginning of the extrusion to place the mold against to start the process, with small curb molds it may only require a cinder block to start.